Obsidian MCP

Remote MCP server for safe ChatGPT-driven note capture into the Aventerica89/Obsidian-Claude vault repo.

MVP behavior

• Search markdown notes in the vault repo.
• Read a note by path.
• Append structured blocks to existing notes, only under ## ChatGPT MCP.
• Create new notes only inside ChatGPT MCP/.
• Auto-commit each write directly to the vault repo.

This is intentionally not a general-purpose filesystem MCP.

Tool surface

• search_notes
  • Find likely markdown notes by title/path and return a short preview.
• get_note
  • Read an existing markdown note from the vault repo.
• append_to_note
  • Append a structured block to an existing note, only under ## ChatGPT MCP.
• create_chatgpt_note
  • Create a new reviewable note only inside ChatGPT MCP/.
• list_allowed_destinations
  • Return the current write constraints and target repo details.

Write semantics

• Existing notes are never overwritten in place outside the reserved section.
• If ## ChatGPT MCP does not exist, it is created at the end of the note.
• Every append block includes timestamp, source: chatgpt-mcp, actor, and needs_review: true.
• New notes are created only under ChatGPT MCP/ with reviewable frontmatter.
• Every successful write creates a direct commit in the vault repo.

Required secrets

Set these Worker secrets before deploy:

wrangler secret put GITHUB_CLIENT_ID
wrangler secret put GITHUB_CLIENT_SECRET
wrangler secret put COOKIE_ENCRYPTION_KEY

Create a KV namespace and update wrangler.jsonc:

wrangler kv namespace create "OAUTH_KV"

Then copy the returned namespace id into wrangler.jsonc.

GitHub Actions deploy

The repo includes deploy.yml, which deploys on pushes to main and on manual dispatch.

Set these GitHub repository secrets before enabling the workflow:

• CLOUDFLARE_API_TOKEN
• CLOUDFLARE_ACCOUNT_ID

The workflow uses cloudflare/[email protected] and runs:

npm ci
wrangler deploy

GitHub OAuth app

Create a GitHub OAuth App with:

• Homepage URL: https://obsidian-mcp.<your-subdomain>.workers.dev
• Authorization callback URL: https://obsidian-mcp.<your-subdomain>.workers.dev/callback

The app must allow the repo and read:user scopes because the authenticated user's token is used to read and write the private vault repo.

This Worker also checks the authenticated GitHub login against ALLOWED_GITHUB_USERNAME, so even a valid OAuth login is rejected unless it matches the configured account.

Local development

Create .dev.vars with:

GITHUB_CLIENT_ID=...
GITHUB_CLIENT_SECRET=...
COOKIE_ENCRYPTION_KEY=...

Run:

npm install
npm run cf-typegen
npm run dev

Run verification locally:

npm run type-check
npm test

ChatGPT connection

After deploy, register the remote MCP endpoint in ChatGPT using:

• MCP Server URL: https://obsidian-mcp.<your-subdomain>.workers.dev/mcp
• Authentication: OAuth

Security boundaries

• Only the GitHub username in ALLOWED_GITHUB_USERNAME can authorize.
• Existing notes can only be appended under ## ChatGPT MCP.
• New notes can only be created in ChatGPT MCP/.
• No overwrite, rename, move, or delete tools are exposed.
• Hidden paths, .obsidian, .git, path traversal, and non-Markdown targets are rejected.